Hello, i have problem with x20cs1070 module. I cannot trasmit and recieve frames because after starting up module have canbusoff value on true. Can anybody help me with this problem? How can i rewrite internal trasmit counter for restarting module?
It would help if you showed the code you’re using. Also, what is the cpu (CS1070) communicating with?
Busoff normally means that there is a problem on the bus physicalwise.
Have you checked the wiring and termination resistors ? CAN must be terminated on both ends using 120 Ohm
Yes both ends are terminated with 120 ohms. But i will check wiring. For each device with CAN bus i can communicate using different app so i think problem is with X20CS1070. After starting up i didnt send anything and this Canbusoff value is already TRUE.
Marek, I normally switch off the system and use a Multimeter to check for the Resistance across the CAN High and CAN Low. With both terminating Resistors installed, you should get approximately 60 Ohms. (2 x 120 Ohms in paralell). The CANHigh or CANLow must have high impedance to CANGnd, also to the shield! (Typical error - a small splice of the shield shorts the signal). Check your LED’s on the CS1070 and compare to the Status LED-table in the X20 Documentation. Note that the CS1070 has an intrinsic terminating resistor, switchable. To state the obvious: CANHigh (terminal top left), CANLow (terminal top right), CAN GND(2nd terminals down, left and right) must go to the corresponding CAN-terminals on the other station.
The other very important issue are that the CAN_Lib library must be installed. Very important is of course the CANOPEN() function in the initialization program, where the device and baudrate are set. Any entries in the logger?
Hi.
We’ve encountered a similar issue with the X20CS2770.
After performing a PLC software update followed by a restart, we sporadically see a BusOff condition on the module.
The strange part: this BusOff cannot be reset, even though CAN communication between other nodes on the bus resumes normally.
The only quick fix we’ve found so far is to completely remove the module from the base and re-insert it.
Unfortunately, we haven’t been able to monitor what’s happening on the physical bus layer during the PLC restart, so we’re not sure what exactly triggers the BusOff in the first place.
That said, the fact that the BusOff flag stays latched and can’t be cleared—even though the bus is back up—feels off.
We’ve discussed this with B&R support. They were able to reproduce the issue partially. Right now, the ball is in our court to identify what’s actually triggering the BusOff.
I’m currently on vacation, but I’ll follow up with more info once I’m back in the office.
HI @Vojtech_Marek, what is status of your topic? can you update us and mark a answer that helped you the most?
Hello everybody, problem was solved by technical support B&R.
There wasn’t problem with SW and technican didn’t know where should be a problem. So we got new card x20CS1070 and everything is going well. After diagnostic we didn’t get any info so I think it was HW problem on device.
So everything is already correct.
